[Positive diagnosis of Leber's hereditary optic neuropathy using molecular genetics].

INTRODUCTION

Leber's hereditary optic neuropathy (LHON) is a bilateral optic atrophy, more common in males than in females. No specific clinical feature or biologic test exists to evidence LHON. We report here the case of a man affected with a nonfamilial bilateral optic atrophy, whose diagnostic remained uncertain for 17 years.

PATIENT AND METHODS

This patient was hospitalized at the age of 27 in order to establish diagnosis. He had an ophthalmologic examination once a year. He was also affected with chronic renal failure. Detection of the G to A mutation at position 11778 of the DNA was assessed by restriction enzyme digestion of amplified genomic DNA.

RESULTS

The 11778 mitochondrial DNA mutation was evidenced, in homoplasmic condition in white blood cells.

DISCUSSION

Molecular biology allows to substantiate the diagnosis of LHON and is relatively easy and cheap. Assessment of mitochondrial DNA provides a useful diagnostic tool for nonfamilial or atypical cases of LHON.